Process for dyeing polyethylene terephthalate of fiber-wool blend



United States Patent 3,027 220 PROCESS F012 DYElNG ltJLYETHYLENE 'IER- EPHTHALATE 0F FEBER WOQL BLEND Ernest Merian, Neumattstrasse 2, Bottrningen, Switzerland; Bruno I. R. Nicolette, Felsplattenstrasse 6, Basel, Switzerland; and Walter Wehrli, Haclrhergstrasse 71, Riehen, near Basel, Switzerland No Drawing. Filed Dec. 5, 1958, Ser. No. 778,273 Claims priority, application Switzerland Dec. It}, 1957 7 laims. (Ql. 8-21) Synthetic fibers are growing steadily in importance, notably for apparel fabrics. Blended fabrics containing natural and synthetic fibers, for example wool or cotton with a polyester fiber, offer special advantages, as they combine the desirable properties of the natural fiber with the tensile strength of the synthetic component.

The introduction of these blended fabrics has presented the colorist with difficult dyeing problems, and one of the results has been an insistent demand for dyestuffs which will dye the synthetic component of these materials to fast shades while reserving the natural fiber. This type of selective dyeing is not easy to achieve on blends of wool and polyester fiber because there are only a few disperse dyestuffs which reserve Wool and at the same time give fast shades on the synthetic fiber.

Most disperse dyestuffs are only superficially attached to the wool, which means that the dyeing on this fiber has very poor fastness to light and rubbing.

It has now been found that the condensation products of terephthaladehydes substituted by alkoxy, alkoxy-alkoxy or alkoxy-alkoxy-alkoxy groups with malonic acid din-itrile or functional derivatives of cyanoacetic acid can, upon conversion into a finely divided form, he applied to blended fabrics from aqueous dispersion to give yellow shades on the synthetic fiber while reserving the wool or cotton component. The dyeings are fast to light, gas fumes, sublimation, water, washing, perspiration, cross dyeing, oxalic acid, dry cleaning, crocking, pressing and heat setting.

The present invention relates to a process for the dyeing of polyester fibers with disperse dyestuffs and it con sists in the use of the condensation pro-ducts of terephthalaldehydes further substituted by alkoXy, alkoxyalkoxy or alkoxyalkoxyalkoxy, groups with malonic acid dinitrile or functional derivatives of cyanoacetic acid, the said condensation products being converted into a finely divided form before application to the fiber.

The condensation products have the formula NC I wherein R stand-s for the radical of a cyano, carboxyalkyl, carboxyhalogenalkyl, carboxycyanoalkyl, carbonyalkoxyalkyl or carboxylic acid amide which may be substituted on the nitrogen atom, and x stands for alkyl, alkoxyalkyl or alkoxyalkoxyalkyl containing 1 to carbon atoms.

For the sake of brevity the condensation products of the above composition are termed terephthalacrylates in the following description of the invention.

The most important products coming under the general name of polyester fibers are the condensation products of terephthalic acid and ethylene glycol which are marketed under the registered trade names Terylene, Dacron, Terg al, Trevira and Diolen.

Terephthalacrylates are converted into a finely divided form by dissolving the technical products in a water-miscible solvent, if desired at high temperature, and adding the resultant solution to water, upon which the product 3,027,220 Patented Mar. 27, 1962 is filtered off, washed and kneaded with a dispersing agent. The paste formed is subsequently dried at normal or re duced pressure or by spray drying.

Another method of converting terephthalacrylates into finely divided form is to grind the dry or moist technical terephthalacrylate on a grinding machine and/ or grinding assistant, after which the product may be dried by one of the methods used in pigment production. The dyeing preparations thus obtained contain the tereph-thalacrylates in particles of the order of magnitude of l r.

In some instances the afiinity of the preparations can be increased by mixing two or more terephthalacrylates converted into finely divided form.

In the following examples the parts are by weight and the temperatures are in degrees Centigrade. The melting points are uncorrected.

Example 1 40 parts of the condensation product of 2.5 -dimethoxyterephthalaldehyde and cyano-acetic acid methyl ester, 40 parts of sodium lauryl alcohol sulfonate and 20 parts of sodium sulfate are ground in a roller mill for 48 hours.

Polyester fibers are dyed as follows: 3 parts of the dye? ing preparation obtained as above are pasted with a little cold, soft water. Cold, soft water is poured on to the paste and the suspension is vigorously stirred and added through a sieve to a dyebath containing 0.5 g./l. of lauryl alcohol sulfonate. 100 parts of scoured Dacron polyester fiber are entered in the bath at 40-50", which is then slowly heated to -100, dyeing being continued at this temperature for l to 2 hours in presence of 5 cc./l. of an aqueous emulsion of a chlorinated benzene.

The dyed material is subsequently rinsed, soaped, rinsed again and dried. The Dacron is dyed to a yellow shade which is extremely fast to sublimation and heat setting, and has good fastness to light, washing, cross dyeing, water, sea water, perspiration, and gas fumes. Wool present in the dyebath is reserved.

Yellow dyeings with similar fastness properties are obtained when in place of a chlorinated benzene an equivalent amount of a hydroxydiphenyl or a salicylic acid ester or a mixture of terephthalic acid dimethyl ester, benzanilide and Glaubers salt is used as carrier, or again when dyeing is carried out at a slightly lower temperature, e.g. 80-90".

Example 2 9.5 parts of the condensation product of 2.5-dimethoxyterephthalaldehyde and cyanoacetic acid ethyl ester are dissolved in 2000 parts of boiling glacial acetic acid. The hot solution is filtered free of minor impurities, and the filtrate run rapidly with thorough stirring into 4000 parts of water and 3000 parts of ice. The suspension formed is filtered oil. The filter residue is washed free of acetic acid and then kneaded with 15 parts of sodium dinaphthylmethanedisulfonate. A finely dispersed paste is obtained which is spray-dried at 60". i

Polyester fibers are dyed at superatmospheric pressure in the following way. The dyebath is prepared as described in Example 1 and parts of scoured Terylene polyester fiber are entered at 40-50". The bath is heated slowly to l20-l30 and dyeing continued at this temperature for about 30 minutes under static pressure. After rinsing, soaping rinsing and drying, at dyeing is obtained which is fast to sublimation and heat setting.

Yellow dyeings having similar fastness properties are obtained when dyeing is carried out at a slightly lower temperature, eg l20, or at slightly higher temperature, e.g. l35l45.

Example 3 75 parts of the condensation product of 2.5'dimethoxy- J) terephthalaldehyde and malonic acid dinitrile are dissolved in 2000 parts of boiling pyridine. The hot solution is filtered free of minor impurities and the dark colored fili The first column gives the meaning of A, the second and third those of X and X and the end column the shade of the dyeing on polyester fibers.

Ex. N0. A= Radical of- X; X; Shade cyanoacetic acid isopropyl ester yellow. cyanoacetic acid-(2-chloro)-ethyl ester D0. cyanoacetic acid amide Do. cyanoaeetic acid ethylamirie Do. malonic acid dinitrile Do.

cyanoacetic acid methyl ester cyanoaeetie acid ethyl ester. eyanoacetic acid isopropyl es cyanoacetic acid-(2-chlor0)-othyl ester cyanoacetic acid-(fz cyanoyethyl ester cyanoaeetic acid amide cyanoacetic acid ethylamide. cyanoacetic acid methyl ester 2-methoxyethoxy 2-methoxyethoxy Do.

2(methoxy)- 2-(methoxy)- Do.

ethoxyethoxy. ethoxyethoxy.

' trate is added rapidly with vigorous stirring to a mixture of 4000 parts of water and 2000 parts of ice. The brilliant yellow suspension thus formed is filtered. The filter residue is washed free of pyridine, kneaded with 115 parts of the powder of sulfite cellulose waste liquor, and the finely dispersed paste dried at 30 in a water-jet vacuum. The product is carefully ground so as to prevent deterioration. The final preparation gives yellow shades on polyester fibers when applied according to the method of Example 2 at 120 under pressure.

The condensation product mentioned in Example 3 is new and is obtained by reacting equimolecular amounts of malonic acid dinitrile and 2.5-dimethoxyterephthalaldehyde in ten times the amount of ethyl alcohol in presence of catalytic amounts of piperidine at 90. The condensation product formed is an orange powder which is sparingly soluble in ethanol and benzene.

Example 4 parts of the condensation product of 2.5-dimethoxyterephthalaldehyde and cyanoacetic acid cyanoethyl ester are ground with 10 parts of sodium dinaphthylmethanedisulfonate and 80 parts of water in a ball mill for 70 hours. A paste is obtained which is dyed on polyester fibers in the manner described in Examples 1 and 2.

Example 5 40 parts of the condensation product of 2.5-dirnethoxyterephthalaldehyde and cyanoacetic acid-(2'-methoxy)- ethyl ester, parts of sodium sulforicinoleate and 40 parts of dextrin are ground in a ball mill for 48 hours. The fine powder obtained is suitable for dyeing polyester fibers at the boil in presence of a carrier, e.g. benzoic acid, or at 130 under pressure. The dyeing methods are the same as those described in Examples 1 and 2. Yellow shades fast to light and washing are produced.

Example 6 40 parts of the condensation product of 2.5-dimethoxyterephthalaldehyde and cyanoacetic acid-(2-ethoxy)- ethyl ester, 20 parts of an albumen degradation product and 40 parts of carboxymethyl cellulose are ground in a roller mill for 48 hours, to give a fine powder. It can be dyed on polyester fibers at the boil in presence of a carrier, e.g. l-hydroxy-2-phenylbenzene, or at 130 under pressure, according to the methods described in Examples 1 and 2, and gives yellow dyeings which are fast to light and washing.

The following table contains further valuable terephthalacrylates which are suitable for dyeing polyester fibers by the methods described in Examples 1 and 2. They correspond to the formula:

Having thus disclosed the invention what we claim is:

1. A process for dyeing a polyethylene terephthalate fiber-wool blend, which consists in dyeing the said blend with finely divided condensation product of alkoxy terephthalaldehyde and a member selected from the group consisting of malonic acid dinitrile and a functional derivative of cyanoacetic acid from an aqueous dispersion, whereby the polyethylene terephthalate fibers are dyed in fast shade while the wool is reserved.

2. A process according to claim 1, wherein the condensation product is of the formula (ROE;

00H; whereby the polyethylene terephthalate fibers are dyed in fast shade while the wool is reserved.

4. A process for dyeing a polyethylene terephthalate fiber-wool blend, which consists in dyeing the said blend with the dyestufl of the formula OHaOOO OOOCHa NC CN whereby the polyethylene terephthalate fibers are dyed in fast shade While the wool is reserved.

5. A process for dyeing a polyethylene terephthalate fiber-wool blend, which consists in dyeing the said blend with the dyestufi of the formula OCH; NC I ON C=CH CH=G NO CN whereby the polyethylene terephthalate fibers are dyed in fast shade while the wool is reserved.

6. A process for dyeing a polyethylene terephthalate whereby the polyethylene terephthalate fibers are dyed in fast shade while the wool is reserved.

fiber-wool blend, which consists in dyeing the said blend with the dyestuff of the formula 0 H CHgCHzOOC C x COOCHZCH' References Cited in the file of this patent C=CH CH=O 5 UNITED STATES PATENTS NC CN 2,669,575 Solonen Feb. 15, 1954 001% 2,889,335 Heckert June 2, 1959 whereby the polyethylene terephthalate fibers are dyed in fast shade while the wool is reserved.

7. A process for dyeing a polyethylene terephthalate 10 fiber-wool blend, which consists in dyeing the said blend with the dyestuif of the formula OTHER REFERENCES Remington: American Dyestufi Reporter, Dec. 22, 1952, pp. 859-860.

Venkataraman: The Chemistry of Synthetic Dyes, vol. II, 1952, page 1206. 11,0000 000cm C=CH OH=C NO ON OCz P-O C 1 UNITED STATES PATENT ()FFICE CERTIFICATE OF CORRECTION Patent No. 3,027, 220 March 27, 1962 Ernest Merian et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the grant, lines 1 to 3, for "Ernest Merian, of Bottmingen, Switzerland, Bruno J. R. Nicolaus, of Basel, Switzerland, and Walter Wehrli, of Riehen, near Basel, Switzerland," read Ernest Merian, of Bottmingen, Switzerland,

Bruno J, R. Nicolaus, of Basel, Switzerland, and Walter Wehrli, of Riehen, near Basel, Switzerland, assignors to Sandoz Ltd.

of Basel Switzerland, a Swiss firm, lines 12 and 13, for "Ernest Merian, Bruno J. R. Nicolaus, and Walter Wehrli, their heirs" read Sandoz Ltd. it successors in the heading to the printed specification, lines 4 to 7, for "Ernest Merian, Neumattstrasse 2, Bottmingen, Switzerland; Bruno J. R. Nicolaus, Felsplattenstrasse 6, Basel, Switzerland; and

Walter Wehrli, Hackbergstrasse 71, Riehen, near Basel, Switzerland" read Ernest Merian, Bottmingen, Switzerland Bruno J. R. Nicolaus, Basel, Switzerland; and Walter Wehrli, Riehen, near Basel, Switzerland, assignors to Sandoz Ltd. Basel, Switzerland, a Swiss firm column 1, line 30, for "terephthaladehydes" read terephthalaldehydes Signed and sealed this 7th day of May 1963.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents 

1. A PROCESS FOR DYEING A POLYETHYLENE TEREPHTHALATE FIBER-WOOL BLEND, WHICH CONSISTS IN DYEING THE SAID BLEND WITH FINELY DIVIDED CONDENSATION PRODUCT OF ALKOXY TEREPHTHALADEHYDE AND A MEMBER SELECTED FROM THE GROUP CONSISTING OF MALONIC ACID DINITRILE AND A FUNCTIONAL DERIVATIVE OF CYANOACETIC ACID FROM AN AQUEOUS DISPERSION, WHEREBY THE POLYETHYLENE TEREPHTHALATE FIBERS ARE DYED IN FAST SHADE THE WOOL IS RESERVED. 